Clinical and biochemical characteristics of the study patients will include demographic data, diagnosis on admission in ICU, APACHE II score on admission and before randomization, medical history as the presence of cardiac insufficiency, hypertension, coronary disease, hepatic insufficiency, diabetes mellitus, hyperlipidemia, nephrotoxic medications which patients receive like antibiotics, NSAID, chemotherapeutic agents, diuretics, inotropic and vasopressor agents, ACE inhibitors, calcium antagonists,mechanical ventilation during ICU, ICU length of stay, and ICU outcome, the need for renal replacement therapy, the quantity of received radiocontrast agent and the route of administration.